I meant inches. I tried to make estimate of size and it seems similar to the large slurry stones offered - they claim to be #1 size bouts of coticule which would make sense based upon what you have said.

Thank you for your reply, it seems that a #1 bout of coticule, as sold as large slurry stones by a couple of sites would indeed work as a pocket hone. For the edge it gives, you can't argue with the price that, for less than $30 arguably makes a damn good finishing stone.